With the progress of the computer technology, more and more applications software are developed to process sophisticated operations including calculation, graphic rendering, audio synthesis, etc., as well as developed a lot of corresponding file types, like multimedia files, text files, etc.
It has already used many methods to prevent the illegal use of the content protected files and commercial software. However, hereto, each of the protection methods has its own drawbacks, so some users can illegally use software by cracking.
The term “Cracking” means breaking the various copy-protection and registration techniques being used.
It is understood by those skilled in the art that the proposed protection way can be used to protect any files which can be stored on data storage device, like:
Data files,
Program Files:                Applications software files.        Systems software files.        
The applications software will be used as a sample to explain proposed protection method. Applications software includes programs that do real work for users. For example, word processors, spreadsheets, and database management systems fall under the category of applications software.
FIG. 5 shows a conventional method for protecting applications software. After obtaining an applications software, the user installs files associated with it on a data storage device 3. As used herein, the data storage device 3 includes any devices able to store digital data therein such as hard disk, compact disk (CD), digital versatile disk (DVD), floppy disk, magnetic tape, flash memory, network memory, etc., and all devices which can be a source to launch and execute the applications software 2. Various files 2 of the installed applications software are in an unprotected state. The user can crack the applications software 2 through a crack program 1, so that the contents for preventing illegal use of applications software files will be modified to achieve an object of illegal use of the software. After modifying the files of applications software 2 so as to release a software protection, the user can execute this applications software through an operation system 4 (for example, Windowso, Linux, Unix). Specifically, the operation system 4 sends instructions to a data storage device controller 5 mounted on a motherboard 6 and operation system 4 can read and execute the files of applications software 2 stored on the data storage device 3. Since the internal protection of this application program has already been removed by the cracking program 1, this application program regards this user as a legal user, and performs its functionalities under the operation system 4. As it can be seen, the crack program 1 can freely remove limitations on the execution of the applications software 2 by modifying the files of applications software 2. Therefore, internal self protection of the applications software can not effectively prevent the illegal use of the applications software.
FIG. 6 shows another conventional method of the protection of applications software. Similar to the method shown in FIG. 5, after obtaining an applications software, the user installs files associated with it on the data storage device 3. At the same time, a dedicated protection software program 7 is also installed on the data storage device 3 for providing a protection against illegal use of the installed applications software 2. However, the dedicated protection software program 7 and an operation system 4 are still in an unprotected state. The user can modify the files of dedicated protection software program 7 and the files of operation system 4 through a crack program 1, so that the contents for preventing illegal use of these files are modified to achieve an object of illegal use of the software. The result of the cracking of the dedicated protection software program 7 and the operation system 4 is a release of the protection of the dedicated protection software program 7 to the applications software 2. The user can execute this applications software through the operation system 4. Specifically, the operation system 4 sends instructions to a data storage device controller 5 mounted on a motherboard 6 and operation system 4 can read and execute the files of applications software 2 stored on the data storage device 3. Since the external protection by the dedicated protection software program 7 has already been removed by the crack program 1, the dedicated protection software program 7 regards this user as a legal user, and the applications software performs its functionalities under the operation system 4. As it can be seen, the crack program 1 can freely remove limitations on the execution of the applications software 2 by modifying the files of the applications software 2, the files of dedicated protection software program 7 and the files of operation system 4. Therefore, the protection which is provided by dedicated protection software can not effectively prevent the illegal usage of applications software.
FIG. 7 shows another conventional method for protecting the applications software. This method uses a hardware control unit “Watchdog” to provide the protection. Similar to the method shown in FIG. 5, after obtaining an applications software, the user installs files associated with it on the data storage device 3. When the applications software is executed, this program sends an instruction to read the Watchdog 8 and receives a corresponding return value from the Watchdog 8. If the return value is correct, then the software is considered to be legally used, otherwise, if the return value is incorrect, then the software is considered to be illegally used and is terminated. However, since various files 2 of the installed applications software and the files of operation system 4 are in an unprotected state, the user can modify the files of applications software 2 and the files of operation system 4 through a crack program 1, so that the contents for preventing illegal use of these files are modified to achieve an object of illegal use of the software. After modifying the applications software files 2 and the files of operation system 4, the user can execute this applications software through the operation system 4. Specifically, the operation system 4 sends instructions to a data storage device controller 5 mounted on a motherboard 6 and operation system 4 can read and execute the applications software 2 stored on the data storage device 3. Since the internal protection of the application program has already been removed by the crack program 1 and the applications software no longer reads the watchdog 8, or the operation system 4 performs interceptions when the applications software reads the watchdog 8 and a correct value is returned, the applications software regards this user as a legal user, and performs its functionalities under the operation system 4. As it can be seen, the crack program 1 can freely remove limitations on the execution of the applications software 2 by modifying the files of applications software 2 and the files of operation system 4. Therefore, a protection to the software by means of the watchdog 8 can not effectively prevent user's illegal use of the applications software.
As it can be seen from FIGS. 5, 6 and 7, there are some protected files and some files involved in the protection procedure for protecting the protected files. Both of types of the files are always in a unprotected state and thus can be illegally modified to remove software protection.
In general, FIGS. 5, 6, 7, show that there exist some basic problems in software protection—software is protected by the same or other software, which can be cracked as soon as its files are installed on hard drive of current PC. It is obvious, that above mentioned problems are true for all kinds of software like data files and program files.